Folding knife and replaceable blade therefor

ABSTRACT

A folding knife having a replaceable blade is provided with an asymmetrically keyed connection for preventing reverse mounting of the blade. The knife includes a blade carrier mounted on the blade pivot and having a blade locking boss thereon preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between folded and extended positions. The blade includes an aperture mounted on the pivot and a tangential slot extending from the aperture for cooperating with the blade locking boss to prevent reversable mounting of the blade on the carrier.

United States Patent Hildebrandt [75] Inventor: William John Hildebrandt, West Simsbury, Conn.

[73] Assignee: The Stanley Works, New Britain,

Conn.

[22] Filed: Aug. 27, 1973 [21] Appl. No.: 391,604

[52] US. Cl. 30/157 [51] Int. Cl B26b 1/02; B26b 5/00 [58] Field of Search 30/125, 155, 156, 157, 30/330, 331, 339, 158, 159, 154, 169

[56] References Cited UNITED STATES PATENTS 304,481 9/1884 Wilson 30/154 1,087,342 2/1914 Yerzley.... 30/157 3,063,147 11/1962 Paparelli 30/154 [4 1 July 29,1975

3,641,667 2/1972 Leopoldi 30/156 X Primary ExaminerAl Lawrence Smith Assistant Examiner-J. C. Peters Attorney, Agent, or Firm-Prutzman, Hayes, Kalb &

Chilton [57] ABSTRACT A folding knife having a replaceable blade is provided with an asymmetrically keyed connection for preventing reverse mounting of the blade. The knife includes a blade carrier mounted on the blade pivot and having a blade locking boss thereon preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between folded and extended positions. The blade includes an aperture mounted on the pivot and a tangential slot extending from the aperture for cooperating with the blade locking boss to prevent reversable mounting of the blade on the carrier.

8 Claims, 5 Drawing Figures FOLDING KNIFE AND REPLACEABLE BLADE THEREFOR BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to folding knives, such as pocket knives and the like and is more particularly concerned with a new and improved folding knife of the replaceable blade type and a replaceable blade for use therein.

Folding blade knives, such as pocket knives, jack knives and the like have been used for many years. Usually the blades in such knives are of a permanent nonreplaceable type. However, in some instances folding knives have been designed so as to permit replacement of the blade portion of the knife as it wears. A typical example of such a structure is the knife described in U.S. patent application Ser. No. 310,365 filed Nov. 29, 1972 by Richard Gilbert and entitled Folding Blade Pocket Knives now U.S. Pat. No. 3,829,967 issued Aug. 20, 1974.

The replaceable blades for folding knives generally are constructed with slotted apertures of key hole configuration, that is, they have a circular aperture for mounting the blade on a suitably configured bladereceiving hub and a radially extending slot connected to the aperture. As described in the aforementioned application the slot is adapted to cooperate with a boss extending radially from the hub along the axis of the blade to cooperatively provide keyed retention of the blade on the knife handle. Unfortunately, such a construction permits the user to install the blade with the cutting edge facing in the wrong direction, thus creating a substantial and serious safety hazard. As will be appreciated, mounting of the blade in such a backward manner will expose the sharp cutting edge of the blade to the hand or fingers of the user as the blade is being folded into the handle. Additionally, once folded, the cutting edge is at least partially exposed along the edge of the handle and can cause injury to the user even in its folded condition. Another potentially dangerous result obtained from reversed or backward mounting of the blade is that the blade will accidentally close against the hand of the user while in use since the normal stops or abutments within the handle are arranged for preventing movement of the blade in the opposite direction. Further, because of the reversal of the blade within the handle the user experiences substantial difficulty in opening the knife to its extended condition.

Accordingly, it is an object of the present invention to provide a new and improved foldable knife and a replaceable blade therefore wherein the blade is mounted on the knife handle in such a manner as to prevent the possibility of backward installation thereby eliminating the numerous safety hazards associated therewith.

Another object of the present invention is to provide a foldable knife and replaceable blade of the type described that utilize a blade carrier having an asymmetrically keyed interconnection that prevents reverse mounting of the blade thereon. Included in this object is the provision for a blade carrier rotatable with the blade and provided with a latching mechanism for holding the blade in both its open and folded positions.

Still another object of the present invention is to provide a new and improved replaceable blade for use in knives of the type described, which blades can be easily replaced in a rapid and facile manner and are constructed so as to render impossible their installation in an improper or backward fashion. Included in this object is the provision for a pocket knife blade having a simple yet extremely effective interlock with a disc-like blade carrier.

Other objects will be in part obvious and in part pointed out in more detail hereinafter.

These and related objects are achieved in accordance with the present invention by providing a folding knife having a handle, a pivot on the handle, a replaceable blade including a cutting edge, a blade carrier mounted on the pivot and having blade locking means thereon preventing relative rotation between the blade and the carrier whereby the blade'and the carrier rotatably move as a unit between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, said blade having mounting means cooperating with said pivot for pivotably mounting the blade and connecting means asymmetric to said pivot and adapted to cooperate with said blade locking means to prevent reversable mounting of the blade on the carrier.

A better understanding of the objects, advantages, features, properties and relations of the invention will be obtained from the following detailed description and accompanying drawing which set forth an illustrative embodiment and are indicative of the way in which the principles of the invention are employed.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a side elevation view, partially broken away and partially in section, illustrating a pocket knife with the blade in its extended position, the knife incorporating the features of the present invention,

FIG. 2 is a fragmentary view of the pocket knife of FIG. 1 with the blade in its folded position,

FIG. 3 is a side view of the blade carrier disc utilized in the pocket knife of FIGS. 1 and 2,

FIG. 4 is an end view of the disc of FIG. 3, and

FIG. 5 is a side view of the replaceable blade used in the knife of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing in greater detail wherein like reference numerals indicate like parts throughout the several figures, the invention is shown as embodied within a folding blade pocket knife of the type described in greater detail in the aforementioned U.S. application Ser. No. 310,365. The disclosure contained therein is incorporated herein by reference.

As shown, the knife 10 is comprised of a narrow elongated handle 12 having complementary side wall members 14,16 held in firm mating relationship by a pair of threaded connectors 18,20 located at opposite ends of the handle and secured within transversely extending bosses, 22,24, respectively. The boss 22 serves as a pivot for a blade 26 mounted thereon so that the blade can be moved from the sheathed position shown in FIG. 2 with the cutting edge 28 of the blade well inside the handle toward the operative position shown in FIG. 1 with the blade in an extended position. The handle side members 14,16, when secured in abutting engagement by the threaded connectors 18,20, define a longitudinal edge slot 30 extending rearwardly from the front end thereof secured by threaded member 18. The slot 30 provides communication with the interior of the blade handle 12 and permits the cutting blade 26 to be moved from its extended position to its sheathed position within the interior of the handle. The threaded connector 18 at the forward or front end of the handle can be easily removed to release the sides 14,16 for pivotal separation in the manner described in the aforementioned application when replacement of the blade 26 is required or when access to a spare blade stored within the handle is desired.

A blade carrier 32, having a central circular aperture 34, is rotatably mounted on the boss 22 and fully housed within the handle 12. As shown in FIGS. 3 and 4, the carrier 32 is of disc-like configuration and has a laterally extending projection 36 of elongated generally elliptical configuration on one side thereof. The projection 36 abuts the central aperture 34 and extends tangentially therefrom to the periphery of the carrier. The blade carrier disc 32 is additionally provided with a pair of peripheral recesses 38,40 at diametrically opposed locations. The recess 38 is slightly larger than recess 40 and includes a latching shoulder 42 having a latching surface 44 inclined slightly from the radius of the disc. The recess 40 is located adjacent side projection 36 and includes a nonradial latch driving surface 46.

The knife blade 26 secured to the handle 12 is an elongated member having a cutting edge 28 extending longitudinally along the bottom edge thereof and a generally circular mounting aperture 48 located adjacent one end thereof. In a conventional manner the blade 26 is provided with a terminal point 50 at the opposite end thereof and with the usual detent 52 for assisting the user in grasping the blade for movement from the sheathed position to the extended position. In accordance with the present invention the blade is further provided with an elongated slot 54 interconnecting with the mounting aperture 48 and extending tangentially therefrom. As shown, the slot 54 is offset from the center line of the blade extending through the aperture 48 and is approximately equal in length to the diameter of the aperture. In the specific embodiment illustrated, the length of the slot 54 is shown as approximately twice that of its width and it extends nonradially from the aperture 48 longitudinally along the blade. However, as will be appreciated, the configuration and the size of the slot may be altered so long as it provides the desired nonreversibility of the blade when mounted on the carrier 32.

The pocket knife further includes a latch member 58 similar in construction and operation to the latch more fully described in the aforementioned patent application. The latch 58 is spring biased into the position illustrated in FIG. 1 and is provided with finger grip portions 60 exposed at the rearward end of the handle for pulling the latch member rearwardly against the bias of return spring 62. The latch 58 is also provided at its forward end with a cam follower surface 64 terminating in a latching shoulder 66 that is biased by spring 62 into a peripheral recess in disc 32. As shown in FIG. 1, the shoulder 66 will engage surface 44 of recess 38 when the blade is in its extended position to lock the disc 32 in the position shown in FIG. 1 and prevent rotation of the blade 26 out of its extended position toward its sheathed position. However, upon rearward movement of latch 58 against the bias of spring 62, shoulder 42 is released permitting counter clockwise rotation as viewed in FIG. 1 of disc 32 and movement of blade 26 toward the sheathed position shown in FIG.

2. As the blade is pivoted, latch 58 may be released so that spring 62 will urge cam follower surface 64 against the periphery of disc 32 until recess 40 is brought into registry therewith. Thereafter movement of blade 26 clockwise as viewed in FIG. 2 toward its extended position will cause driving surface 46 of disc 32 to engage the cam follower surface 64 and drive the latch 58 rearwardly against the bias of spring 62 until latch shoulder 66 falls off shoulder 42 into recess 38 and the blade 26 bears against the internal stop 68.

The pocket knife 10 illustrated in FIG. 1 also includes a storage compartment within the handle 12 for spare blades and the like. The storage compartment is formed partly by the latch 58 which includes a triangular recess 70 for the pointed end of the spare blade and a laterally projecting boss 72 having a configuration corresponding to the mounting aperture 48 and slot 54 of the blade 26, the boss 72 being arranged so that the spare blade is mounted with its cutting edge facing away from the open slot 30 extending longitudinally along the blade handle 12. The boss 72 also serves as a stop when blade 26 is folded into its sheathed position.

As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teaching of the present invention.

I claim:

1. In a folding knife having a handle, a pivot on the handle and a replaceable blade including a cutting edge, said blade being mounted on the pivot for pivotal movement through an arc of about between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, the combination comprising a blade carrier mounted on the pivot and having blade locking means thereon preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between said folded and extended positions, said carrier being enclosed within the handle and movable between said positions in response to movement of said blade, said blade having mounting means cooperating with said pivot for pivotably mounting the blade, said mounting means including means asymmetric to said pivot and adapted to cooperate with said blade locking means to mount said blade for pivotal movement of said locking means and said blade as a unit and to prevent reversible mounting of the blade on the carrier.

2. The folding knife of claim 1 wherein one of said cooperative blade locking means and asymmetric means is a protruding boss and the other is a recess for receiving said boss, said recess and boss cooperatively interlocking the blade on the carrier.

3. The folding knife of claim 1 wherein both the carrier and the blade are apertured for coaxial mounting on the pivot.

4. The folding knife of claim 1 wherein the carrier and the blade are coaxially mounted within the handle, the blade has a longitudinal center line extending through the pivot and the cooperating blade locking means and asymmetric means are offset from said longitudinal center line.

5. A replaceable knife blade for use in a folding knife having a pivot and a blade carrier including a boss extending asymmetrically to said pivot comprising an elongated blade body, a cutting edge extending along said body, mounting means adjacent one end of said body for mounting the blade on the carrier for pivotal movement about the pivot to permit folding of the blade and blade connecting means asymmetrically associated with said mounting means for cooperative engagement with said boss to require a specific nonreversible, mounted orientation of the blade on the carrier of the knife, wherein the mounting means and the blade connecting means are interconnected in the form of an asymmetrical keyhole, said mounting means comprising an enlarged circular aperture portion of the keyhole for mounting on the pivot and said blade connecting means comprising a relatively narrow elongated stem portion extending asymmetrically from said enlarged aperture, said stem keyhole portion cooperating with said boss to prevent reversible mounting of said blade on said carrier.

6. In a folding knife having a handle, a pivot on the handle and a replaceable blade including a cutting edge, said blade being mounted on the pivot for pivotal movement through an arc of about 180 between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, the combination comprising a disc-like blade carrier mounted on the pivot and having blade locking protruding boss thereon preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between said folded and extended positions, said carrier being enclosed within the handle and movable between said positions in response to movement of said blade, said blade having mounting means cooperating with said pivot for pivotably mounting the blade, said mounting means including a recess asymmetric to said pivot and adapted to cooperatively interlock with said blade locking boss to prevent reversible mounting of the blade on the carrier.

7. In a folding knife having a handle, a pivot on the handle and a replaceable blade including a cutting edge, said blade being mounted on the pivot for pivotal movement through an arc of about between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, the combination comprising a blade carrier disc mounted on the pivot and having blade locking elongated boss extending tangentially of the pivot preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between said folded and extended positions, said carrier being enclosed within the handle and movable between said positions in response to movement of said blade, said blade having mounting means cooperating with said pivot for pivotably mounting the blade, said mounting means including means asymmetric to said pivot and adapted to cooperate with said blade locking boss to prevent reversible mounting of the blade on the carrier.

8. A replaceable knife blade for use in a folding knife having a pivot and a blade carrier including a boss extending asymmetrically to said pivot comprising an elongated blade body, a cutting edge extending along said body, an aperture adjacent one end of said body for mounting the blade on the carrier for pivotal movement about the pivot to permit folding of the blade and a slot extending tangentially to said aperture and interconnected therewith for cooperative engagement with said boss to require specific nonreversible mounted orientation of the blade on the carrier of the knife. 

1. In a folding knife having a handle, a pivot on the handle and a replaceable blade including a cutting edge, said blade being mounted on the pivot for pivotal movement through an arc of about 180* between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, the combination comprising a blade carrier mounted on the pivot and having blade locking means thereon preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between said folded and extended positions, said carrier being enclosed within the handle and movable between said positions in response to movement of said blade, said blade having mounting means cooperating with said pivot for pivotably mounting the blade, said mounting means including means asymmetric to said pivot and adapted to cooperate with said blade locking means to mount said blade for pivotal movement of said locking means and said blade as a unit and to prevent reversible mounting of the blade on the carrier.
 2. The folding knife of claim 1 wherein one of said cooperative blade locking means and asymmetric means is a protruding boss and the other is a recess for receiving said boss, said recess and boss cooperatively interlocking the blade on the carrier.
 3. The folding knife of claim 1 wherein both the carrier and the blade are apertured for coaxial mounting on the pivot.
 4. The folding knife of claim 1 wherein the carrier and the blade are coaxially mounted within the handle, the blade has a longitudinal center line extending through the pivot and the cooperating blade locking means and asymmetric means are offset from said longitudinal center line.
 5. A replaceable knife blade for use in a folding knife having a pivot and a blade carrier including a boss extending asymmetrically to said pivot comprising an elongated blade body, a cutting edge extending along said body, mounting means adjacent one end of said body for mounting the blade on the carrier for pivotal movement about the pivot to permit folding of the blade and blade connecting means asymmetrically associated with said mounting means for cooperative engagement with said boss to require a specific nonreversible, mounted orientation of the blade on the carrier of the knife, wherein the mounting means and the blade connecting means are interconnected in the form of an asymmetrical keyhole, said mounting means comprising an enlarged circular aperture portion of the keyhole for mounting on the pivot and said blade connecting means comprising a relatively narrow elongated stem portion extending asymmetrically from said enlarged aperture, said stem keyhole portion cooperating with said boss to prevent reversible mounting of said blade on said carrier.
 6. In a folding knife having a handle, a pivot on the handle and a replaceable blade including a cutting edge, said blade being mounted on the pivot for pivotal movement through an arc of about 180* between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, the combination comprising a disc-like blade carrier mounted on the pivot and having blade locking protruding boss thereon preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between said folded and extended positions, said carrier being enclosed within the handle and movable between said positions in response to movement of said blade, said blade having mounting means cooperating with said pivot for pivotably mounting the blade, said mounting means including a recess asymmetric to said pivot and adapted to cooperatively interlock with said blade locking boss to prevent reversible mounting of the blade on the carrier.
 7. In a folding knife having a handle, a pivot on the handle and a replaceable blade including a cutting edge, said blade being mounted on the pivot for pivotal movement through an arc of about 180* between a folded position with the cutting edge housed within the handle and an extended position with the cutting edge exposed, the combination comprising a blade carrier disc mounted on the pivot and having blade locking elongated boss extending tangentially of the pivot preventing relative rotation between the blade and the carrier whereby the blade and the carrier rotatably move as a unit between said folded and extended positions, said carrier being enclosed within the handle and movable between said positions in response to movement of said blade, said blade having mounting means cooperating with said pivot for pivotably mounting the blade, said mounting means including means asymmetric to said pivot and adapted to cooperate with said blade locking boss to prevent reversible mounting of the blade on the carrier.
 8. A replaceable knife blade for use in a folding knife having a pivot and a blade carrier including a boss extending asymmetrically to said pivot comprising an elongated blade body, a cutting edge extending along said body, an aperture adjacent one end of said body for mounting the blade on the carrier for pivotal movement about the pivot to permit folding of the blade and a slot extending tangentially to said aperture and interconnected therewith for cooperative engagement with said boss to require specific nonreversible mounted orientation of the blade on the carrier of the knife. 